Sides.java

# Write a java program to create an abstract class named Shape that contains an empty method named numberOfSides( ). 
# Provide three classes named Rectangle, Triangle and Hexagon such that each one of the classes extends the class Shape. 
# Each one of the classes contains only the method numberOfSides( ) that shows the number of sides in the given geometrical structures.
abstract class Shape
{
            abstract void numberofsides();
}
class Rectangle extends Shape
{
            void numberofsides()
            {
                        System.out.println("Number of sides of Rectangle is : 4");
            }
}
class Triangle extends Shape
{
            void numberofsides()
            {
                        System.out.println("Number of sides of Triangle is : 3");
            }
}
class Hexagon extends Shape
{
            void numberofsides()
            {
                        System.out.println("Number of sides of Hexagon is : 6");
            }
}
class Sides
{
            public static void main(String args[])
            {
                        Shape s;
                        s=new Rectangle();
                        s.numberofsides();
                        s=new Triangle();
                        s.numberofsides();
                        s=new Hexagon();
                        s.numberofsides();      
                       
            }
}